Steam boiler



Gv A. BRYAN STEAM BOILER Sept. 22, 1931.

Filed Aug. 13, 1929 2 Sheets-Sheet l NY \mv Fm G. A. BRYAN STEAM BOILER 2 Sheets-Sheet 2 Filed Aug. 13, 1929 owooooooo oooooooooo IlEIZE INVENTOR ATTORNEY Sept. 22, 1931.

Hair

STATES PATENTOFFICE GEORGE A. BRYAN, OF PERU, INDIANA, ASSIGNOR TO BRYANSTEAM ,OORPORATION,

A CORPORATION OF NEVI MEXICO STEAM BOILER My invention has reference to a water tube boiler to be used in conjunction with a domestic heating system. In particular the invention relates to that type of boiler in which the water tubes are bent to run horizontally back and forth across the boiler,

above the combustion chamber.

In constructing small boilers of this type, it is the practice to cast the water dome, water ends and water ring or base as separate castings, which castings are secured together by means of bolts. The tubes which are bent to run horizontally back and forth across the entire width of the boiler are con-. nected at their upper ends to the water dome and at their lower ends to the water ring, and are self-supporting. In constructing boilers of this type of larger capacity, such for instance, as a boiler having a capacity 29 sufficient to supply the heating system ofa large apartment house or a factory, it is impractical merely to increase the size of the castings and of the tubes correspondingly. Tubes having runs of the required length would no longer be self-supporting and would sag. The castings required for these larger boilers, especially for the water dome and water ring would be so large as to be practically prohibitive because of the ex- 39 pense of manufacture and difliculty and eX- pense of handling.

By my invention, I have overcome the difficulties encountered in, constructing water tube boilers of the type in which a plurality of nested tubes are bent to run back and forth over the combustion chamber of a capacity large enough. to supply a large apartment house or a factory. I construct a boiler of this type from a plurality of inter- 4o changeable castings.

An important feature of my invention is the fact that the reverse bends in the water tubes are contained in planes inclined to the vertical, the bends in successive tubes being -15 inclined in opposite directions.

Another important feature of my invention is'the fact that alternate tubes overlap at the center so that the tubes interengage to prevent any direct opening to the stack whlch might otherwise occur.

Other features of my invention will here- I inafter more particularly appear.

Specifically, I employ a construction in which the boiler may be considered as constituting two identical parts separableupon a longitudinal,vertical plane, the two parts being united through the water ends. Each partcomprises a plurality of castings and a' plurality of nested tubes. The tubes are bent to run substantially horizontally back and forth across half the width of the boiler which is well Within thelimitin-which they are self-supporting. The successive bends'of a tube are containedin perpendicular planes inclined to the vertical, the bends of successive tubes. being inclined in opposite directions, and being nested one within the other. The tubes are connected to the castings in staggered relation so that alternate tubes over lap atthe'center of the boiler. the tubes interengaging at the center, thereby preventing a direct opening from the combustion chamber to thestack'which might'otherwise occur. Thus, the two parts, which might be considered to be complete units in themselves, unite to form a boiler of double the capacity of either half. The interchangeability of the arts permits the manufacture of these boilers at a minimum of expense since only half the number of patterns are required relative to the number of castings required, and the castings are of such a size: as to be readily and easily handled and compactly arranged for shipment.

Incidentally by constructing the boiler in this manner it may be readily and quickly assembled at the location of installation and thereby reduce the expense of'shipping and handling. i i i A detailed description of one embodiment of my invention will be given in connection with. the accompanying drawings in which:

Fig. 1 is a plan of a boiler embodying my invention; 7 I

Fig. 2 is a side elevation of the same, part being in section;

Fig. 3 is a transverse, central sectional elevation;

Fig. tis a front elevation;

plan of a modified form of a boiler which is symmetrical on either side of a longitudinal, central, vertical plane. The boiler is made up from a plurality of castings which constitute the dome, water ends, and the base headers. The dome comprises two identical castings 1 and 2. These castings are hollow, as shown, to accommodate the water and the steam generated in the boiler. At intervals, flue openings extend through the dome, the walls 3 of which strengthen the casting and resist the internal pressure of the steam. Each of the castings l and 2 is provided with a steam outlet 4, to which a delivery pipe of the heating system is attached by flange connectors in the usual way. The casting 1 is provided with a smooth vertical surface 5 which is at the front of the boiler and has threaded openings therein to receive. the -connections to the water gage, pet cocks, and pressure gage. A similar surface 6, on the casting 2, at the rear of the boiler has a threaded opening to receive the pipe leading to the safety valve. At the front and rear thereof, the castings 1 and 2 have openings 7 in the lower wall through which they communicate with the water ends 8 and 9. The dome and water ends are secured together by bolts 10.

The water ends 8 and 9 are cast in rectangular form as shown and are provided with through openings .11, the walls of which support the walls of the water ends against the internal pressure of the water and the steam. At the lower end, near the center thereof, the outer walls of the castings 8 and 9 are pro vided with openings 12 with which the return pipe of the heating system is adapted to be placed in communication. At the lower corners, alignedopenings are provided in the inner and outer walls of the water ends. The openings in the outer walls serve as washouts, the walls of which are threaded to receive threaded plugs. Across the opening in the inner wall there is provided a web 13 which is bored to receive a tie rod 14 that serves to tightly connect. the water ends 8 and 9 to the base headers 15 and 16.

The base headers 15 and 16 are identical and are substantially square in cross section. They are provided, near each end, with webs 17 similar towebs 13 on the water ends 8 and 9. The upper wall of the base headers, from the longitudinal center to the outer wall, is made thicker than the rest and is bored at intervals to receive the ends of the water tubes 18, the other ends of which are received in similar openings in the lower wall of the water dome in that casting which is on the same side of the longitudinal central vertical plane as the base header to which one end of the tube is connected. The tube openings in the dome and base header are staggered relative to the center of the boiler, alternate holes being slightly nearer the center of the boiler, so that alternate tubes overlap at the center.

The tubes 18 are bent in such a manner that when in position in the boiler, they run substantially horizontally back and forth across one half of the boiler underneath the casting 1 or 2 to which they are connected. The reverse bends of a tube are inclined at an angle to the vertical, the successive bends of a tube being contained in planes perpendicular to each other. The tubes are arranged in pairs, the reverse bends of the individual tubes of a pair being inclined to the vertical in opposite directions and cross at the points of bending, so that these tubes of a pair are nested, with their bends one within another. One of the tubes of each pair is connected to the base header and water dome through the openings in the outer row, the other being connected through openings in the inner row, thereby allowing for the crossing of the tubes at the bends and at the same time causing one tube of each pair to overlap the center of the boiler. Thus, in the illustrateden'ibodiment,reverse bends, at the outside of the boiler, of the tubes connected in the openings constituting the outer row are inclined toward the rear of the boiler, and the reverse bends, at the outside of the boiler, of the tubes connected in the openings constituting the inner row are inclined toward the front of the boil er. This arrangement of tubes in pairs such that the tubes of each pair cross each other at an angle of approximately ninety degrees at the bends thereof greatly increases the capacity of the boiler. The overlapping of the bends of alternate tubes at the center of the boiler prevents the formation of a direct passage from the combustion chamber to the flue at the center of the boiler. The arrangement of the nested tubes is such that any tube in the outer row may be replaced without disturbing any of the other tubes and any tube in the inner row may be removed and replaced by merely removing the tube in the outer row with which it forms a pair. The ends of the tubes are connected to the castings by special nipple fasteners 19 which fit tightly in the openings in the castings. The nipples connecting the upper end of the tube to the dome are provided with stand-pipes 20 which extend above the level of the water end and eject the steam formed in the tube above the water in the boiler.

In Figures 5 and 6, a modified form of base ring is shown. The base ring consists of two identical castings 21 and 22 each casting forming one half of a rectangle being divided along the longitudinal center line of the boiler."

Openings are provided in the upper wall of the longitudinal side portions to accommodate the ends of the tubes. The upper walls of the end portions are provided with openings 23 by means of which they communicate with the water ends.

The water end to be used with the modified form of base ring is illustrated in Figures 7 and 8. The water end consists of a hollow rectangle casting 24 having openings in the lower end which are adapted to be aligned with the openings in the water header and similar openings in the upper end adapted to be aligned with the openings in the castings 1 and 2. Openings 25 with which the return pipe of the heating system is adapted to be placed in communication are provided in the sides of the water ends. Each water end may, if desired, be constructed in two parts and united through the return openings thereby naking each half of the boiler complete in itself.

T he base headersor water base of the boiler is adapted to rest on the upper surfaces of the walls of the combustion chamber, the boiler being supported thereby.

It is obvious that various changes may be made in the construction illustrated and above particularly described within the principle and scope of my invention as expressed in the appended claims.

I claim:

1. A water tube boiler comprising a water dome. a base header, and a plurality of nested tubes bent to run back and forth over the combustion chamber connected at one end. to the water dome and at the other end to the base header, the bends in successive tubes being inclined to the vertical in opposite directions.

2. A water tube boiler comprising a. water dome, a base header, and a plurality of pairs of nested tubes bent to run back and forth over the combustion chamber, each tube be ing connected at one end to the water dome and at the other end to the base header, the bends in the tubes constituting a pair being inclined to the vertical in opposite directions so that the tubes of a pair cross each other at the bends.

A water tube boiler comprising two counterpart castings constituting a dome, two counterpart castings constituting a base header, two counterpart castings constituting water ends, one water end casting connecting each dome casting and base header casting, the two castings of the dome, base header and water ends being symmetrically related and symmetrically connected, and two symmetrically related sets of counterpart water tubes, one set symmetrically connecting each dome casting and base header casting and the tubes of each set being bent to run horizontally back and forth only underneath its own dome casting.

4;. A water tube boiler comprising a two part: casting constituting the dome, a base header for each dome casting, the two castings and; headers being symmetrically related, and two sets of watertubes, one set connecting each casting and header and each set including a plurality of pairs of nested tubes bent to run back and forth underneath its own casting, the bends in the tubes constituting a pair being inclined to the vertical in opposite directions so that the tubes of a pair cross each other at the bends.

5'. A Water tube boiler comprising a two part casting constituting the dome, a base header for each dome casting, the two castings and headers being symmetrically related, and two sets of water tubes, one set connecting each casting and header and each set including a plurality of pairs of nested tubes bent to run back and forth underneath its own casting, the bends in the tubes constituting a pair being inclined to the vertical in opposite directions so that the tubes of a pair cross each other at the bends and the tubes being connected to the castings in staggered relation so that the bends of alternate tubes in either set overlap the center line of the boiler.

6. A water tube boiler including only two counterpart parts constituting a dome, only two counterpart parts constituting a base header, and only two counterpart parts constituting water ends, one water end part connecting each dome part and base header part, the two parts of the dome,base header and water ends being symmetrically related to one another and being symmetrically arranged with reference to said other parts to which they are respectively connected.

7'. A water tube boiler comprising a water dome, a base header, and a plurality of pairs of nested tubes bent to run back and forth over the combustion chamber, each tube being connected at one end to the water dome and at the other end to the base header, the ends of the tubes being connected to the water dome and to the base header in staggered relation and the bends in the tubes constituting a pair being inclined to the vertical in opposite directions so that the tubes of a pair cross each other at the bends.

8. A water tube boiler comprising two similar symmetrically related parts constituting a two-part dome, two similar symmetrically related parts constituting a two-part base header, each base header part being beneath one of the dome parts, and two symmetrically related sets of similar water tubes, one set connecting each dome part and base header part below it and each set including a pair of nested tubes bent to run back and forth underneath its own dome part, the ends of the tubes being connected to the dome part and to the base header part in staggered relation and the bends in the tubes constituting a pair being inclined to the Vertical in opposite directions so that the tubes of a pair cross each other at the bends and 5 the two sets of tubes being disposed relatively to each other so that the bends of alternate tubes in either set overlap the bends of the tubes in the other set and the center line of the boiler.

9. A water tube boiler comprising two similar symmetrically related parts constituting a two-part dome, two similar symmetrically related parts constituting a two-part base header, each base header part being beneath one of the dome parts, two similar symmetrically related water ends each symmetrically connecting together both dome parts and both base header parts, and two symmetrically related sets of similar water tubes, one set connecting each dome part and base header part below it and each set including a pair of nested tubes bent to run back and forth underneath its own dome part, the ends of the tubes being connected to the dome part and to the base header part in staggered relation and the bends in the tubes constituting a pair being inclined to the vertical in opposite directions so that the tubes of a pair cross each other at the bends and the two sets of tubes being disposed relatively to each other so that the bends of alternate tubes in either set OXGIliLP the bends of the tubes in the other set and the center line of the boiler.

In witness whereof, I hereunto subscribe my signature. 1

GEORGE A. BRYAN. 

